davek9

This simple part stopped my Twin Screw from going to HELL on Saturday

PET calls it out as: Adapter Cyl 1-4

Went for a 6 mile shake down ride after connecting up some monitoring gauges into the cockpit.

Half a block from home that metal sleeve came "un-glued"

I hear Porsche still glues them on newer up to '08 911's (GT3's?) and owners are/need to get them welded if they want to track the car's.

Did some searching, is JB Weld still the recommended fix or should I get it TIG welded?


Thanks in advance,

Dave

davek9

pics added

skpyle

I JB welded mine on the Red Witch, then bought the older one piece elbow from Roger for less than $30.

OTR18WHEELER

davek9

Thanks Seth, wasn't sure if the older cast one piece part was still available, I'll contact Roger tomorrow and get one into next day mail if he's has them in stock

Then take the two I have to my TIG guy who is doing the ones on the 911, I'm not that good using my own TIG unit yet

Dave

skpyle

I cured the JB Weld with a heat gun on WAY too high a temp. The epoxy turned brown. I no longer trusted it. Hence, a new part.

I never said I knew what I was doing...

SeanR

I've JB welded several with no failures so far. I've not had to order any new ones as I bought a handful of the one piece ones many years back so no clue what they come as. Will ask Rog today.

worf928

The one-piece part is what you get from Porsche when you order. At least it was about three months ago.

re: GT3. I guess the rear-engine engineers don't talk to the front-engine engineers. Makes no sense. In other a$$-engined news, the 991s have problems with infant mortality on vacuum change-over valves. These are exactly the same as the vacuum valve for the resonance flap on '87+ with a modern electrical connector. I think I've seen one flappy solenoid valve failure. Robust part for us. Chinese for 991s?

worf928

Follow-up: at this point I don't wait for them to fail. They get changed preemptively when I find them.

Does anyone know exactly when the one-piece part became standard? Sometime before '90 and after '87 is certain.

davek9

Thanks Dave and Sean for adding to the conversation.

Dave, I was under the impression that the one piece adapter is an "older" part that was superseded by the two piece bonded adapter.

Thanks,

Dave K

Adk46

I know it's heresy to suggest a MacGyver-style approach, but would doing something to alter the smooth "co-axiality" (as in the tuning slide of a trumpet) to prevent a gusher, at least? A whack with a punch, or a little squeeze, perhaps. It's easy to mess up trumpet slides this way.

worf928

Perhaps PAG flipped back-and-forth? I dunno. But my impression is the opposite.

I have multiple data points for '87 and '90+. Curiously, I don't see many '88s or '89s, but numerous '87s and '90+. I've two '90 GT engines in the garage now, along with my '91 and all three had the one piece from the factory.

I have no data for pre-'87.

If this archeology gets serious, I can check a '93 and '94 today. Another '94 on Thursday and a '95 on Saturday.

davek9

I know of at least one '93 GTS, two '87 and two '88's that I've worked on, all having the two piece and have never see a one piece on an '85 - '86.

Wonder what the cost of a Billet part would be

Thanks,

Dave

skpyle

For what it is worth, I bought a new one piece water adapter from Roger back in the middle of June.

928 104 713 02 Water Fitting Adapter Cylinder 1 to 4.
$30.14

WAY cheaper than billet.

dr bob

I haven't had any issues with the one that came on my 12/88 build '89 car. Now I need to go look.

For those contemplating a JBWeld "fix", perhaps the most critical requirements start with "C": Cleanliness, Clearance, and Concentric. The first is obvious. The second is a reminder that there needs to be enough room all the way around the insert for a film of the epoxy. The original fitment is a slight interference fit, and the tube pops out when there isn't enough interference. The last "C" is concentric, as in the hole in the casting needs to be round, the tube needs to be round, and with the second "C" the clearance needs to be relatively even all the way around.

Or just buy the correct $30 one-piece fitting from your favorite 928 parts purveyor. Ship/delivery time is only marginally greater than the prep and cure time for the temporary glue-up. And you needed some other stuff anyway.